Blade



Aug. 25, 1942. R. M. scHAEFr-:R

BLADE Filed Jan. 4, 1941 i `Patented Aug.v 25, 1942 BLADE Robert M. Schaefer, Racine, Wis., assignor to Twin Disc Clutch Company, Racine, Wis., a corporation of Wisconsin Application January 4, 1941, Serial No. 373,065

12 Claims.

My invention relates to blades for hydraulic power transmission units such as hydraulic couplings, hydraulic torque converters, and similar units wherein energy is transmitted by and to blades through a hydraulic medium.

By way of example, my invention will be described in connection with blades for torque converters. Heretofore, it has been common practice to make .these blades from drawn brass stock, which is cut in lengths equal to the length of the finished blades plus the supporting trunnions, the latter being turned to the proper diameter. The transverse sectional profile of these blades varies from comparatively simple shapes to those having complex curvatures which are designed'for maximum elciency. The manufacture of the latter` in particular requires special machine equipment, which means high unit cost, and the problem becomes more complicated and more expensive with blades of larger size. Moreover, in blades of this character, there is a weight problem involved due to the solid nature of the part and the latter aspect is further reected in high material cost due to the character of the metal.

It is, therefore, the principal object of my inventionto provide la blade which is bent into shape from a stamping and in which the trunnion pin or pins serve to strengthen the blade section.

A further object is to devise a blade which is hollow. and, therefore, considerably lighter than solid blades, and in which provision is made for deaerating the blade interior during operation to prevent unbalancing of the rotor to which the blade is connected.

A further object is to provide a blade of the character indicated which can be made from relatively inexpensive materials, such as sheet steel for the blade proper and cold rolled steel stock for the trui-mien.

These and further objects of my invention.will be set.forth in the following specication, reference being had to the accompanying drawing, and the novel means by which said objects are efectuated will be definitely pointed out in the claims.

In the drawing:

Figure l isan elevation of my improved blade.

Fig, 2 is an end View of the blade shown in Fig. 1.

Fig. 3 is ia transverse section of that portion of the trunnion pin which is included between the ends of the. blade.

Fig-4 is a plan view of the stamping from 'which the blade is formed.

Figs. 5 and 6 are elevation and end views, respectively, of a modified form of blade.

Fig. '7 is a fragmentary elevation of a rotor, partly in section, showing my improved blades attached thereto.

Fig, 8 is a section along the line 8-8 in Fig. 7.

Referring to Figs. 1 to 4, inclusive, the numeral I0 designates my improved blade which is generally in the form of an openended shell comprising a pair of opposed, impervious wallsl I and I2', which in the particular shape of blade shown are, respectively, concave and convex. Along one side of the blade, these walls are connected by a curved end wall I3 which constitutes the inlet edge of the blade and at the opposite edges the walls are brought together to form the relatively sharp tip I4. Considering the other edges as the ends of the blade, one of the walls,

for example the wall II, is provided with a pair of spaced tongues I5 at each end edge, these tongues being formedby slitting the Wall II in' wardly from the end edges and thereafter bending the tongues inwardly of the blade so as to lie lgenerally normal to the plane of the Wall. .The

bending of these tongues creates deaerating notches I6 for a purpose hereinafter explained, and the tongues are employed to initially locate a trunnion pin Il which extends completely through the blade in bearing and secured relation to the walls Ii and I2 and has its opposite ends projecting beyond the ends of the blade for suitable mounting in a carrier. If the dimensions of the blade or the operating conditions require, a second trunnion pin may also be employed and this pin would be spaced from the pin I1. In order to provide maximum strength in the trunnion pin for any given section of blade, I preferably atten the bearing sides of the pin, as indicated by the numeral i8 in Fig. 3, along that part which is included between the ends of the blade, or the indicated intermediate portion of the pin may possess an appropriate elliptical cross section or be otherwise deformed. The bearing surfaces of the trunnion pin are shaped and angularly related to conform to the opposed blade walls along the areas of contact. This expedient provides the maximum diameter for the projecting ends of the pin and at the same time facilitates the insertion of the pin between the walls H and I2 as hereinafter described.

The body of the blade. it is preferably made from a flat steel stamping I9 which, in the case of the blade illustrated in Fig, 1, possesses a rectangular shape and may be made from oiled sheet steel of appropriate gauge, dependent upon the longitudinal edges to provide the tongues I5- which are then bent normal to the stamping,

after which the stamping is reversely-bent intermediate its ends and shaped to the .desired proiile. In this connection, it will be understood that my invention is not restrictedto a blade having the proille illustrated in Fig. 2, as the more generic aspectsof the invention are directed to an inexpensive and light-weight blade, in which the trunnion pin serves to strengthen the blade section by passing completely through the blade. After the stamping has been bent, its adjacent-end edges are flattened cold, or coined, in order to'insurethat, when the indicated ends are secured together, the abutting portions of the stamping will be suiiiciently reduced in thickness to provideA the required shape at the tip' of the blade.

The trunnion pin I1 is then inserted between the wallsJI and I2 and positioned endwise so that its ends project the same distance beyond the ends of the blades and also so that the'pin is positioned between each pair of tongues I5. The adjacent ends of the reversely bent stamping I9 are then temporarily secured to each other by means of one or more spot welds, generally indicated by the numeral 20 in Fig. l, and the complete assembly is then passed through a hydrogen furnace where the pin I1 is brazed to the walls I I and I2 and the ends of the stamping I9 are brazed to each other to form the tip Il.

than that illustrated in Fig.'1. the length being measured in thedirectlon of the iiuid iiow across the blade. In this modification, the numeral 2l designates the blade generally, which includes a trunnion pin 22 that is mounted and secured to rthe blade in themanner above described, and

, which are not provided with shroud rings, the

trunnion pin need only extend beyond one open end of the blade for mounting in a rotor. The blade is then carried by a cantilever support.

I claim:

1. A blade comprising a hollow shell whose opposite walls are shaped to the desired proiile, and a cylindrical trunnion pin extending between the walls and beyond an end of the shell for mounting in a carrier, the pinbeing secured The foregoing arrangement of parts may be employed with any desired blade proiile and for impeller or pump blades, turbine or runner blades, and iixed or reaction blades and for any type of power unit in which powerl is transmitted by means of the impingement of a iluid medium on a blade. In the case of the impeller and turbine blades, it is necessary to provide some means for insuring a complete deaeration of the interior oi.' the blades, otherwise the rotor to which the blades are secured may be 'unbalanced during rotation. 'I'his result is achieved by the use of the deaerating notches I6. In'this connection, it will be understood that while blades of this character are more or less snugly fitted between the opposite walls of -the carrier, dimensional discrepancies may result in small openings between edges of some of the blades and the walls of the carrier and the absence of such openings in other similar locations around theunit. Under these conditions, it will be obvious that, unless deaerating openings lwere provided, the more snugly fitted blades -would retain any air thatA may havecollected therein when the hydraulic power unit is out of service, and this mass of air would not be .evacuated when lthe unit began operation'. The

provision'of the notches I6 completely obviates any operating diillculty in this respect. The inventionis not restricted to placing the notches I8 along the edges -of the blades, for it is contemplated that these openings,v as well as the tongues I3, may be otherwise located, vincluding intermediate positions in the blade surface. v In Figs. 'I and 8 are illustrated a. characteristic' mounting ofthe blades I0 between. the spaced, impervious walls^25 of the rotor 26 which secured to a shaft 21. A

In Figs. 5 and 6, there is illustrated a modiiled construction that embodies the advantages of the blade heretofore described and, in addition, in-

to and bearing on the shell and being slightly ilattened along the bearing surfaces to secure maximum diameter ofthe projecting end of the trunnion.

2. A blade for hydraulic power units comprising a pair of opposed, impervious walls connected along a pair of their opposite edges, respectively, and otherwise spaced from each other, and one or more deaerating notches provided in an edge of one of the walls communicating with the interior of the blade.

3. A blade for hydraulic power units comprising a pair of opposed, impervious walls connected along a pair of their opposite edges, respectively. and otherwise spaced from each other, a pair ot spaced tongues bent out of the body of one -of the walls along each edge other than the connected edges, the bending forming a pair of deaerating notches communicating with the interior of the blade, and a trunnion pin extending across the blade between each pair of tongues and disposed between and secured to the walls, the tongues serving to position the pin while being secured to the blade.

4.'A blade comprising a hollow shell whose opposite walls are shaped to theA desired profile. atrunnion pin extending between the walls and beyond at least one end of the shell for mounting in a carrier, the pin being secured to the walls, and an insert' block located within the shell and secured to the walls for receiving a pin mounted in the carrier wall whereby twisting effort on the trunnion pin is reduced.

5. A blade comprising a pair of opposed walls :connected along a pair of their opposite edges,

respectively, and otherwise spacedv from each for mount Y a carrier, the pin bearing on and being secured to 'the opposite walls and spaced from ysaid opposite edges to thereby strengthen the shellaagainst-uid pressure.

6. AA blade comp g a nat stamping reversely bent intermediate ts ends, the ends being secured together andthe opposite walls being otherwise separated, 'anda trunnion pin extending between and secured to the walls in spaced relation to the reversely bent portion to thereby strengthen the shell'against uid pressure. -'1. A blade comprising a pair of opposed wallsl 10.- In a power unitvforihydraulicallytransmitting power, the combination' of a rotor-having a pair of spaced, annular, impervious walls and a plurality of circumferentiallvj'- spaced' bladestpair of spaced, annular, impervious` walls anda plurality of circumferentially spaced blades :llt-

ting snugly. betweenthe walls to deiine a plurality of passages through which fluid passes when .the rotor is rotated. each blade comprising a hollow shell having deaerating apertures adtingsnugly between 'the'walls to denea plurality of passages through which iluidpasses when the rotor is rotated, each blade comprising a hollow shell having` a deaerating aperture in a wall thereof communicating with theinteriorof the shell, the air in thev-shell being discharged through-thefaperture `when the rotor is first ro tated and replaced by uid to prevent unbalancing ofthe rotor.

11. Av blade-for aihydraulic power transmission unit comprising a nat stamping reversely bent intermediate its ends, theends being secured togetherand the opposite walls-being otherwise separated ,and including one or more deaerating jacent the ends thereof communicating with the interior of the shell, the air in the shell'being discharged through the apertures during the early stages of rotation of the rotor and replaced by the fluid to prevent unbalancing of the rotor.

9. In a power unit for hydraulically transmitting power, the combination of a rotor having a pairvof spaced, annular, impervious walls and a plurality of circumferentially spaced blades lltting snugly between the walls to dene a plurality of passages through which iiuid passes when the rotor is rotated, each blade comprising an open ended, hollow shell whose ends abut the walls and including one or more deaerating notches in an edge of the shell wall communicating with the interior of the shell, the air in the shell being discharged through the notches when the rotor is rst rotated and replaced by iluid to prevent unbalancing of the rotor.

notches in an edge of one of the walls'other than the secured ends to provide a means of communication with the interior of the blade.

12. A blade for a hydraulic power transmission unit comprising a flat stamping reversely bent intermediate vits ends, the ends being secured together and the opposite walls being otherwise spaced from each other, a pair of spaced tongues bent out of the body of one ot the walls along each edge other than the connected ends, the bending forming a pair of deaerating notches providing a means of communication with the interior of the blade, and a trunnion pin extending across the blade between each pair of tongues and disposed between and secured to the walls, the tongues serving to position the pin while being secured to the blade.

ROBERT M. SCHAEFER.

2,293,768.-Robert M. Schae er, Racine, Wis. BLADE. Patent dated August 25, 1942. Disclaimer ed 'June 4, 1943, by the assignee, Twin Disc Olm'ch Company.

Hereby enters this'disclaimer to claims 5 and 6 of said patent;

[OcialGazce June 29, 1943.] 

